U.S. patent number 4,246,734 [Application Number 05/951,031] was granted by the patent office on 1981-01-27 for fold down multi-purpose vehicle seat back core with inmolded metal reenforcing member.
This patent grant is currently assigned to K & M Plastics Inc.. Invention is credited to William E. Brennan, Alva E. Fogle, Jr., Jacque Passino.
United States Patent |
4,246,734 |
Fogle, Jr. , et al. |
* January 27, 1981 |
Fold down multi-purpose vehicle seat back core with inmolded metal
reenforcing member
Abstract
A seat back core for a vehicle having a fold down seat which is
also required to serve as a load floor. The core is blow-molded and
formed with a pair of parallel spaced walls having tying links
extending between the walls to strengthen and rigidify the core but
not to prevent flexure thereof. There is a peripheral closing wall
around the core. An elongate metal member is incorporated into the
core at the time that it is blow-molded and becomes a permanent
part of the core. It serves to limit the flexure of the core,
provide additional strength and may serve as an anchor for
securement of hardware.
Inventors: |
Fogle, Jr.; Alva E. (Buffalo
Grove, IL), Brennan; William E. (Troy, MI), Passino;
Jacque (Orchard Lake, MI) |
Assignee: |
K & M Plastics Inc. (Elk
Grove Village, IL)
|
[*] Notice: |
The portion of the term of this patent
subsequent to March 6, 1996 has been disclaimed. |
Family
ID: |
25491179 |
Appl.
No.: |
05/951,031 |
Filed: |
October 18, 1978 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
845845 |
Oct 27, 1977 |
4142757 |
|
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|
Current U.S.
Class: |
52/309.16;
108/901; 296/66; 296/63; 297/DIG.2 |
Current CPC
Class: |
B62D
25/2054 (20130101); B29C 49/4802 (20130101); B60N
2/36 (20130101); B29C 49/20 (20130101); B60N
2/3072 (20130101); B29C 2049/206 (20130101); B29L
2031/30 (20130101); B29C 2049/2065 (20130101); B29C
49/04 (20130101); B29L 2031/771 (20130101); Y10S
297/02 (20130101); B29C 2049/2017 (20130101); B29C
2049/4812 (20130101); Y10S 108/901 (20130101); B29C
2049/4805 (20130101) |
Current International
Class: |
B29C
49/48 (20060101); B29C 49/20 (20060101); B60N
2/30 (20060101); B60N 2/32 (20060101); B60N
2/36 (20060101); B62D 25/20 (20060101); B29C
49/04 (20060101); E04C 001/00 () |
Field of
Search: |
;52/309.16 ;296/63,66
;108/51R,901 ;297/DIG.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Pate, III; William F.
Parent Case Text
CROSS REFERENCE TO COPENDING APPLICATION
This is a continuation-in-part of an application having the title:
"FOLD DOWN MULTI-PURPOSE VEHICLE SEAT BACK CORE OR THE LIKE
AUTOMOTIVE STRUCTURAL MEMBER", Ser. No. 845,845, filed Oct. 27,
1977 by the same applicants and assigned to the same assignee now
U.S. Pat. No. 4,142,757.
This application incorporates the copending application above
identified by reference.
Claims
What is desired to secure by Letters Patent of the United States
is:
1. A load floor for the core of a fold down vehicle seat or the
like automotive structural member comprising
A. a hollow blow-molded member of synthetic resin whose overall
thickness is substantially less than its size and which is
generally rectangular in configuration,
B. including a pair of generally parallel walls extending over
substantially all of said member and having a peripheral connecting
wall joining them around the member,
C. a plurality of tying links extending between the parallel walls
on the interior of the member and comprising:
i. each such link being integral with a first parallel wall and
comprising an indented formation having a bottom which is generally
parallel with said first parallel wall from which the indented
formation extends,
ii. the depth of the indented formation being such as to carry the
said bottom into engagement with the interior surface of the second
and opposite parallel wall and forming a web therewith which is
approximately twice the thickness of either of the parallel
walls,
iii. the indented formation being produced during the blow-molding
operation whereby the said bottom and the said portion of the
respective parallel walls are permanently welded together,
D. said tying links being distributed throughout the entire area of
said member whereby to rigidify and strengthen said member
throughout its area to serve as weight support,
E. said member having means to accommodate if not enable securement
of automotive hardware, and
F. at least one of said indentations extending a substantial
distance along the length of said load floor and having a channel
shaped reenforcing member of metal locked to the bottom and sides
thereof.
2. The structural member as claimed in claim 1 in which at least
the last-mentioned indentation has its bottom engaged with the
unindented interior surface of the opposite parallel wall.
3. The structural member as claimed in claim 1 in which the channel
shaped reenforcing member has straight side arms angled
outward.
4. The structural member as claimed in claim 3 in which the free
edges of the side arms have flanges thereon and the side walls of
the said last-mentioned indentation have pockets confining said
flanges.
5. The structural member as claimed in claim 1 in which the length
of the last-mentioned indentation is greater than the length of the
reenforcing member leaving a free space to permit sliding of the
reinforcing member when the structural member cools after
molding.
6. A load floor for the core of a fold down vehicle seat which
comprises:
A. a hollow blow-molded member of synthetic resin whose overall
thickness is substantially less than its size and which is
generally rectangular in configuration,
B. including a pair of generally parallel walls extending over
substantially all of said member and having a peripheral connecting
wall joining them around the member,
C. a plurality of indentations in at least one parallel wall spaced
throughout the area of the member and each forming a tying link
extending between the parallel walls, each tying link comprising
the walls of the indentation and having the bottom of the
indentation welded to the interior of the wall opposite that one
from which it is indented,
D. one indentation extending along the length of the member having
a cross-section comprising a flat bottom and angled outward walls
and
E. a sheet metal reenforcing member of generally channel
construction conforming to and locked into the bottom of the
indentation and somewhat less than coextensive in length
therewith.
7. The load floor as claimed in claim 6 in which the free edges of
the channel arms of the reenforcing member have outwardly extending
flanges engaged in pockets formed in the side walls of the one
indentation.
8. The load floor as claimed in claim 6 in which the ends of the
one indentation are provided with areas to enable sliding of the
reenforcing member when the load floor cools after molding.
9. The load floor as claimed in claim 6 in which the depth
dimension of the side walls of the one indentation are greater than
the equivalent dimension of the channel arms of the reenforcing
member whereby to provide blocking formations along the length of
the one indentation preventing removal of the reenforcing
member.
10. The load floor as claimed in claim 7 in which the depth
dimension of the side walls of the indentation are greater than the
equivalent dimension of the channel arms of the reenforcing
member.
11. The load floor as claimed in claim 6 in which there is a
plurality of reenforcing members, each in a separate
indentation.
12. The load floor as claimed in claim 6 in which there is a
plurality of reenforcing members arranged end to end in said one
indentation.
Description
FIELD AND BACKGROUND OF THE INVENTION
The copending application Ser. No. 845,845 is incorporated herein
by reference. The field and background of the invention herein are
the same as in the copending application but for the aspect which
is mentioned below. The disclosure of the copending application is
considered also included herein.
The seat back core of the copending application is intended to
deflect under pressure which gives it great strength, the flexure
being effected by resilience and being followed by recovery. Metal
cores will assume permanent set if deflected.
Deflection increases with the length of the seat back core and in
the cores intended for vehicles larger than the so-called compact
cars this deflection may be undesirable. Even in smaller vehicles
it may be desired to limit the deflection or prevent it
entirely.
The invention solves these problems by the use of a relatively
stiff reenforcing steel member that is incorporated into the
core.
Given a core that is constructed in accordance with the teachings
of the copending application, securing a reenforcing member to the
core by suitable fastening means such as bolts passing through the
core and clamping the member in place would be the obvious way of
attaching the bar. This requires additional operations, weakens the
core and may not have the desired effect because of necessity it is
fastened at specific points.
The invention utilizes a method of making the core which is not
obvious and which results in the inclusion of a steel structure
member that is completely married with the core along its entire
length. The bar is installed into the mold before the molding
process takes place so that the plastic material flows around the
bar and locks it in position. This cannot be done normally because
of the difference between the modulus of shrinking of the plastic
and the modulus of expansion and contraction of steel. The solution
by the invention is an exquisite one that considers the structure
of the resulting core and the manner in which the steel member is
disposed in the core.
In the blow-molding of relatively large elongate members such as
the seat core of the invention, shrinkage occurs to a high degree
in the direction in which parison has been formed. Logically the
parison is blown in the long dimension of the seat core. The
shrinkage resulting during the curing of the molded object can be
as much as 0.018 inch for each inch of length. Considering that a
typical seat core will extend across the interior of a vehicle cab
and have a length of 50 inches and more, the shrinkage can amount
to nine tenths of an inch. Steel expands with heat and contracts
with cold, but the contraction during the molding process is
insufficient to match the shrinking of the resin.
Since it is essential that the steel reenforcing member be locked
into the seat core, the problem of preventing the core from bowing
seems insurmountable. According to the invention, the construction
of the reenforcing member and the manner in which it is placed in
the mold during the molding process obviates this problem by
permitting the member to slide relative to the seat core during
curing.
Prior art which is known comprises the references cited during the
prosecution of the copending application and others which are
mentioned in the specification of the said copending application.
These include the following:
______________________________________ 3,669,496 Chisholm June 13,
1972 Class 297/445 3,334,941 Krasinski et al Aug. 8, 1967 Class
296/66 3,317,238 Smoll May 2, 1967 Class 296/69 3,742,995 Confer et
al July 3, 1973 Class 150/.5 3,705,931 Confer et al Dec. 12, 1972
Class 264/89 3,869,239 Confer Nov. 30, 1972 Class 425/302 B
______________________________________
SUMMARY OF THE INVENTION
A seat back core for a vehicle having a fold down seat which is
required to serve as a load floor in which the core is blow-molded
and formed as a unitary member having a pair or parallel walls
spaced apart and connected by means of tying links that extend
generally throughout the area of the load floor on the interior
thereof and are formed during the molding process. There is a
peripheral wall around the core and the core has means for enabling
the securement of hardware thereto.
In order to provide for additional rigidity and strength, a
channel-shaped steel bar is incorporated into the mold at the time
that the core is being blow-molded and is locked in place during
this process. The bar is arranged in the direction of the maximum
shrinkage of the core and is disposed in a groove so that it can
slide slightly during curing of the resin and will not result in
the core being bowed as it comes out of the mold.
Different structures of the steel bar are used. The bar is locked
in place permanently during the molding process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary top plan view of a seat back core
constructed in accordance with the invention;
FIG. 1 is a sectional view through the seat back core of FIG. 1
along the line 2--2 and in the indicated direction;
FIG. 2 is an enlarged fragmentary sectional view taken generally in
the same manner as FIG. 2 but showing a modified form of the
invention;
FIG. 4 is similar to FIG. 3 but of still another modified form of
the invention;
FIG. 5 is a diagrammatic top plan view of a seat back core of
modified form and showing the manner of mounting two steel
reenforcement members in the core;
FIG. 6 is a diagrammatic top plan view similar to that of FIG. 5
but showing another arrangement for mounting the steel
reenforcement members;
FIG. 7 is a fragmentary sectional view through one part of a mold
for blow-molding a seat back core showing the construction of
molding surface of the part for carrying a reenforcing member and
showing the member in exploded disposition as it is being installed
into the mold part; and
FIG. 8 is a fragmentary perspective view of the mold projection at
one end thereof showing the construction to enable the reenforcing
member to slide during the curing of the seat back core.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention comprises the seat back core of the copending
application but with a reenforcing steel structure molded into the
core permanently during the molding process. The invention also
includes the process for making such a seat core.
The details of the construction and the function of the several
parts of the basic seat core are contained in the copending
application which has been incorporated herein by reference. The
structure which is necessary to be explained for the best
disclosure of the invention will be repeated briefly herein.
In FIG. 1 and its sectional view in FIG. 2 are shown a seat back
core 10 which is blow-molded in the manner described generally in
the copending application and more in detail herein. The particular
structure 10 has a front wall 12 provided with indentations of
several types and a planar rear wall 14. The front and rear walls
are connected by a peripheral wall 13 all around. The rear surface
16 is plain in this example.
The indentations include frusto-pyramidal indentations at 18 along
the upper edge, transverse elongate rectangular indentations at 20,
and an elongate rectangular indentation 22 which extends throughout
the majority of the length of the core 10. All indentations are
tapered towards their bottoms and each results in a doubled
thickness of the plastic walls 12 and 14 where they come together
and are welded in place during the molding process as explained in
the copending application.
These indentations all provide the connecting links which tie the
walls 12 and 14 together, a typical tying link being indicated at
24 and being formed by the surrounding walls of the indentation 18.
The tying links of different shaped indentations will generally
follow the shape of the indentation. Thus, the tying links of the
rectangular indentations 20 comprise rectangular formations 26.
There may be smaller indentations such as at 28 providing smaller
tying links at locations 30 where hardware is intended to be
secured.
The indentation 22 extends substantially along the entire length of
the seat core 10 and it has a steel reenforcing member 32 locked
into its side walls, having been molded into core 10 at the time of
its formation. The member 32 is of channel construction and may be
stamped or bent from cold rolled sheet steel of 14 gauge steel
(0.0747' thick). The channel side arms 33 are bent outward as best
seen in FIG. 2 to conform closely to the tapered configuration of
the indentation 22. The dimensions are chosen so that the depth of
the channel member 32 is substantially less than the depth of the
indentation 22 so that when molded there will be plastic material
engaging along the free edges of the channel arms 33. This results
in the locking engagement which prevents removal of the reenforcing
member 32.
In a practical example the depth of the indentation 22 measured
along the angled side walls was about seven eighths inch while the
equivalent dimension of the side arms 33 of the reenforcing member
was about one half inch, resulting in a blocking bead or formation
34 about three eighths of an inch wide along the entire length of
the reenforcing member 32.
It will be noted that the length of the indentation 22 is
substantially greated than the length of the member 32 so that
there is a free portion at 36 formed at opposite ends of the
indentation 22. This space is provided primarily to enable the
sliding movement of the member 32 during the curing of the core 10
which occurs primarily after it has been removed from the mold and
is cooling. This freedom to slide prevents the reenforcing member
from being forced against any part of the seat core 10 which could
result in bowing of the core or separating the walls.
In FIGS. 3 and 4 two different constructions are shown. The core
10' of FIG. 3 uses a reenforcing member 32' which is similar in
construction to the member 32 in that it has the outwardly bent
channel arms 33' to conform to the walls of the indentation 22' but
in addition has small lips or flanges 38 along the free edges of
the channel arms. With this form of reenforcing member, when molded
there will be a more positive locking action because of the
formation of the pockets 40 by plastic that tries to follow the
contours of the member 32'. It should be recalled that in
blow-molding the parison is a tube of plastic having a
substantially uniform wall throughout and when that wall is blown
into a mold it tries to follow every contour of the mold. As will
be explained, during the molding process the reenforcing member 32'
is acting as an integral part of the mold and the parison wall will
envelop the same and produce the locking pockets 40 on opposite
edges of the member 32'.
The core 10" of FIG. 4 uses a reenforcing channel member 32" that
has substantially right angle arms 33 each provided with a small
lip 38' that is locked into a pocket 40" during the molding of the
core 10" in the same manner as the core 10'.
FIGS. 3 and 4 are on a larger scale than FIG. 2 so that it is more
readily seen that the tying links produced by the indentations are
formed at locations where the bottom ends of the tying links will
weld to the opposite wall and form a double thickness thereat.
Thus, the indentation 22' produced an elongate tying link 32' that
extends the majority of the length of the core 10' and has the
thickened portion 44' at its base.
In molding the cores 10, 10' and 10" where, for example, all of the
indentations are formed in one wall of the core and the other is
substantially unindented, the mold will be made out of two parts,
one of which is flat-faced and the other of which has projections.
In FIGS. 7 and 8 there are illustrated fragments of a mold which
has the projections. In the views, the projection 50 is intended
for one of the indentations 18, for example, and the projection 52
is intended for the indentation 22 or 22'. These are formed solid
with the body of the mold 54 and will be of suitable configuration
and dimensions to provide the desired indentations.
The projection 52 has the same contour and dimensions at its ends
as the projection 50 thereby providing for the indentation ends to
produce the free space at 36 mentioned above and indicated in FIG.
1. This forms a slight protuberance 56 at each end of the
projection 52. The depth of the protuberance 56 is approximately
the same as the thickness of the channel shaped reenforcing member
which is to be mounted to the projection 52.
In fabricating the mold part 54, the projection 52 can be cast or
machined from the block or may be separately formed and attached by
machine screws. If removable, different forms of projections can be
used with the same mold base 54.
The mold base 54 is intended to accommodate the reenforcing member
32 or 32' which is laid onto the cutaway portion shown on the
projection 52 and held in place as the mold is used. Obviously a
new channel shaped reenforcing member will be used each time that a
seat core is formed since the act of molding locks the reenforcing
member to the core. In FIG. 7, a reenforcing member 32' of the
construction shown in FIG. 3 is poised to be mounted on the
projection 52. It is dimensioned so that it will not reach the
upper surface 58 of the base 54. Its length is such that it will
fit between the end protuberances 56 so that when the seat core is
molded, there will be nothing to prevent the channel shaped
reenforcing member 32' from freely sliding endwise. The
protuberance 56 will form the end of the indentation 22 or 22' as
deep as the normal indentations and hence leave the space 36 for
movement of the reenforcing member 32 or 32'.
The maximum shrinking of the seat core will occur along its length
and hence it is best that the reenforcing member be disposed to be
able to slide along this dimension. Actually, the utility of the
reenforcing member is maximum when disposed lengthwise of the seat
core.
The securement or mounting of the reenforcing member 32, 32' or 32"
to the mold part before bringing the parts together is capable of
being achieved by different means. Self-adhering tape may be used
under the members; vacuum openings may be utilized to hold them in
place; and a simple magnetic arrangement could be used. In FIG. 7,
permanent magnets 62 may be mounted along the length of the
projection 52 flush with the upper surface to hold the reenforcing
member 32 or 32' in place during the molding process.
The reenforcing members 32, 32' and 32" are intended to prevent
flexure of the seat core and to strengthen the same. Different
arrangements can be used for different purposes.
In FIG. 5 there is illustrated a core 100 which has two reenforcing
members 102 and 104 molded therein to provide great strength and
stiffness.
In FIG. 6 there is illustrated a seat core 106 in which there are
two reenforcing members 108 and 110 arranged end to end but
separated in the center. In this case, the only place where flexure
can take place is in the center; hence the core 106 will be
permitted to flex but only to a limited extent.
It is pointed out that the addition of metal members to the
blow-molded seat core does not add substantially to the cost
thereof because once the mold has been constructed, it requires
only a few seconds to mount the reenforcing member into the mold
before bringing the parts together in the molding machine. This is
not the same effect as fabricating the conventional sheet metal
seat core because, when the seat core of the invention is withdrawn
from the mold, it is complete but for the attachment of hardware.
The reenforcing members may be drilled, tapped or provided with
studs and the like (entering suitable sockets formed to clear in
the mold base) so that hardware may be attached directly thereto if
desired when assembling the same to the vehicle.
Variations are capable of being made without departing from the
spirit or scope of the invention as defined in the appended
claims.
* * * * *